Rack and pinion assembly

Abstract

The pinion is of two-piece construction, the two pieces being identical and nestably mated to define a recess, therebetween, which is interrupted by abutments, and which confines an abutment-engaging pin. Each piece has a plurality of teeth projecting therefrom, and the pieces are so mated that the teeth pluralities project form opposite sides of the formed pinion. A generally U-shaped rack, having teeth formed on the confronting surfaces of the parallel limbs thereof, is in mesh with the pinion, and the pin penetrates an input shaft upon which the pinion is mounted. As the shaft is turned in one direction, the pin drivingly engages the abutments of only one pinion piece, to cause the teeth of the latter to drive the rack in one, given direction. Too, if the shaft is turned in the opposite direction, the pin engages the abutments of only the other pinion piece, to cause its teeth to drive the rack in the same, one, given direction.

We claim: 
     
       1. A rack and pinion assembly, comprising: a guide; and   a rack slidably engaged with said guide; wherein said guide comprises means for constraining said rack to linear motion thereof relative to said guide;   pinion means, drivingly engaged with said rack, for causing linear translation of said rack coincident with rotation of said pinion means;   a shaft, (a) disposed for torqued, driving rotation thereof about an axis in clockwise and counter-clockwise directions, and (b) comprising means for causing a driven rotation of said pinion means coincident with, and as a consequence of, rotation of sai shaft; and   means coupling said shaft and said pinion means together for transmitting torqued rotation of said shaft to said pinion means; wherein   said pinion means and said coupling means comprise means cooperative for causing said rack to translate in only one direction in response to rotation of said shaft in (a) a clockwise direction, and/or (b) a counter-clockwise direction.   
     
     
       2. A rack and pinion assembly, according to claim 1, wherein: said pinion means comprises a pinion gear of two, mating pieces;   each of said pieces comprises an annulus having a plurality of teeth formed thereon.   
     
     
       3. A rack and pinion assembly, according to claim 2, wherein: said rack is substantially U-shaped, having a pair of substantially parallel limbs having mutually confronting surfaces, and a web integral with, and bridgingly joining said limbs;   said confronting surfaces each have a plurality of teeth formed thereon; and   said teeth of one of said pieces are drivingly meshed with said teeth of one of said confronting surfaces, and said teeth of the other of said pieces are drivingly meshed with said teeth of the other of said confronting surfaces.   
     
     
       4. A rack and pinion assembly, according to claim 2, wherein: said mating pieces of said gear are rotatably journalled on said shaft.   
     
     
       5. A rack and pinion assembly, according to claim 1, wherein: said rack is slidably disposed relative to said guide, as aforesaid, for movement in said one direction in response to rotation of said shaft; and further including   a bearing surface; and   means interposed between said bearing surface and said rack biasing said rack against movement in said one direction.   
     
     
       6. A rack and pinion assembly, according to claim 5, wherein: said biasing means comprises compression springs.   
     
     
       7. A rack and pinion assembly, according to claim 1, wherein: said coupling means is confined within said pinion means.   
     
     
       8. A rack and pinion assembly, according to claim 1, wherein: said pinion comprises a pinion gear formed of a plurality of mating pieces; and   said pieces of said plurality are identical.   
     
     
       9. A rack and pinion assembly, according to class 8, wherein: said pieces of said plurality are just two in number.   
     
     
       10. A rack and pinion assembly, comprising: a guide; and   a rack slidably engaged with said guide; wherein   said guide comprises means for constraining said rack to linear motion thereof relative to said guide;   pinion means, drivingly engaged with said rack, for causing linear translation of said rack coincident with rotation of said pinion means;   a shaft, rotatable about an axis in clockwise and counter-clockwise directions, for causing rotation of said pinion means coincident with rotation of said shaft; and   means coupling said shaft and said pinion means together for imparting any rotation of said shaft to said pinion means; wherein   said pinion means and said coupling means comprise means cooperative for causing said rack to translate in only one direction in response to rotation of said shaft in (a) a clockwise direction, and/or (b) a counter-clockwise direction;   said pinion means comprises a pinion gear of two, mating pieces;   each of said pieces comprises an annulus having a plurality of teeth formed thereon;   said pinion means, coupling means, and said rack comprise means which cooperate to cause one of said mating pieces to rotate in common with said shaft, and to cause the other of said mating pieces to rotate counter to rotation of said shaft.   
     
     
       11. A rack and pinion assembly, comprising: a guide; and   a rack slidably engaged with said guide; wherein   said guide comprises means for constraining said rack to linear motion thereof relative to said guide;   pinion means, drivingly engaged with said rack, for causing linear translation of said rack coincident with rotation of said pinion means;   a shaft, rotatable about an axis in clockwise and counter-clockwise directions, for causing rotation of said pinion means coincident with rotation of said shaft; and   means coupling said shaft and said pinion means together for imparting any rotation of said shaft to said pinion means; wherein   said pinion means and said coupling means comprise means cooperative for causing said rack to translate in only one direction in response to rotation of said shaft in (a) a clockwise direction, and/or (b) a counter-clockwise direction;   said pinion means comprises a pinion gear having a substantially annular recess, with a peripheral wall, formed therein;   said pinion gear further having abutments extending, inwardly, relative to said pinion gear, and projectingly from said peripheral wall; and   said coupling means comprises a pin, set in said shaft in traverse of said axis, for contacting engagement thereof with said abutments.   
     
     
       12. A rack and pinion assembly, comprising: a guide; and   a rack slidably engaged with said guide; wherein   said guide comprises means for constraining said rack to linear motion thereof relative to said guide;   pinion means, drivingly engaged with said rack, for causing linear translation of said rack coincident with rotation of said pinion means;   a shaft, rotatable about an axis in clockwise and counter-clockwise directions, for causing rotation of said pinion means coincident with rotation of said shaft; and   means coupling said shaft and said pinion means together for imparting any rotation of said shaft to said pinion means; wherein   said pinion means and said coupling means comprise means cooperative for causing said rack to translate in only one direction in response to rotation of said shaft in (a) a clockwise direction, and/or (b) a counter-clockwise direction;   said pinion comprises a pinion gear formed of a plurality of mating pieces;   said pieces of said plurality are identical;   each piece of said plurality thereof comprises an annulus;   each said annulus having an annular recess formed therein;   said recess having a peripheral wall;   said wall being interrupted by a pair of abutments extending therefrom; and   said annulus further having a plurality of teeth projecting therefrom.   
     
     
       13. A rack and pinion assembly, according to claim 12, wherein: said annulus has a given thickness; and   said teeth have a thickness differing from said given thickness.   
     
     
       14. A rack and pinion assembly, according to claim 13, wherein: said given thickness is substantially half said differing thickness.   
     
     
       15. A rack and pinion assembly, according to claim 12, wherein: said coupling means comprises a pin, set in said shaft in traverse of said axis, for contacting engagement thereof with said abutments;   said pin has a given thickness; and   said recess has a depth of substantially half said given thickness.